1. Field of the Invention
The present invention relates to an inkjet recording method.
2. Description of the Related Art
Along with the rapid development of information technology industries in recent years, various information processing systems have been developed, and at the same time, recording methods and recording apparatuses that are pertinent to the respective information processing systems are also being put to practical use. Among these, inkjet recording methods have been widely used because of the advantages in that recording is possible on various materials to be recorded, that the hardware (apparatus) is relatively inexpensive and compact, and that the methods are excellent in quietness. Furthermore, in recording performed using an inkjet recording method, it is even possible to obtain so-called photograph-like high-quality recorded matter.
In recent years, recording media in which an ink receiving layer has a porous structure are being increasingly put to practical use. It is described that these recording media have excellent rapid-drying properties and give high glossiness.
However, the demand for high image quality is increasing more and more, and therefore, an inkjet recording medium capable of producing even clearer high-quality images (with high density) and also having excellent storability, is desired.
As for printing methods for obtaining high-density images, for example, Japanese Patent Application Laid-Open (JP-A) No. 2000-247022 and JP-A No. 2006-181954 disclose methods for obtaining high-density recorded images by regulating the pore size of the ink receiving layer.
Furthermore, various investigations to find other methods to obtain high-density images are also being conducted with respect to the inkjet ink. For example, JP-A No. 2005-336489 describes a method of obtaining printed images having high density by controlling the content or type of a water-soluble organic solvent contained in the ink.
On the other hand, in the inkjet recording system, when an ink containing a solvent that is easy to volatile under the temperature and humidity conditions of usage (for example, an ink making use of water as a solvent, or the like), or an ink containing large amounts of dispersed insoluble components or polymer compounds (for example, an ink making use of a pigment or a resin microparticle dispersion, or the like) is used, there occurs a phenomenon in which the solvent in the ink volatiles from the nozzles during printing or while waiting to print, to cause lowering of the solvent concentration in the ink around the nozzles, and the ink viscosity increases. In the case where the ink viscosity around the nozzles increases, fluid resistance increases inside the nozzles, so that ejection failure occurs, such as a fluctuation in the volume of flight or direction of flight of the ejected ink droplets, or stopping of ejection. As a result, a shift in the dot position on the printing medium or an error in the dot size, or even absence of dots may be brought about.
In regard to such problems, JP-A No. 63-41152, JP-A No. 1-108056, Japanese National Phase Publication (Laid-Open) No. 2000-512233, and Japanese National Phase Publication (Laid-Open) No. 2003-505281 propose a technology of constantly circulating the ink of non-ejecting nozzles and ejecting nozzles even during printing, so that a decrease in the concentration of the ink solvent around the nozzles is prevented.